I do not think VTA can be optimized for each record solely on the basis of vinyl thickness. I will defer to Peter on this, but my tentative answer is “yes.”
I agree with this. Vinyl thickness only accounts for about 1.5mm. My range is 3.0mm. I think cutting angle must also be considered. I have LPs of the same thickness that have slightly different ideal arm heights or SRAs. From this I conclude that the cutting angle must be slightly different. I could be wrong, the system may not be transparent enough, or I may be fooling myself.
Of course none of this is "breaking news". Ron must be referring to his belief system that was shattered by evidence. Ron and I met with Alan Goodwin at Goodwin's High End. We discussed the whole issue of adjusting arm height. I told Alan that I was one of the "crazies" who change arm height for different LPs, but was clear that I find the setting once, make a note of the setting, and go to it the next time I listen to that particular LP. I do not start from scratch each time. His response was that of course this stuff matters, and it is easily audible. He said cutting angle was more a factor than was thickness. He said it was a fact and not even worth debating. The only debate was whether or not the individual vinyl listener was willing to go to the trouble to make adjustments. For Alan this was all old news.
Alan Goodwin was described to me ten years ago by my SME dealer as "one of two guys left in Massachusetts who could properly set up a turntable." The other guy was the dealer himself who sold to me and set up my first SME turntable. I learned a lot from that guy.
Yes, Fransisco, 1.5mm is a huge amount of arm height adjustment. That is roughly 3/10th of one degree. The LP that we had been playing was a thin record. Ron wanted to hear Brubeck's "Take Five". We played it and it was obvious to me that the SRA was wrong. I made a quick guess that the arm should be raised to my setting of 18mm which is often, but not always, the best setting for thick LPs. It sounded much better. Perhaps I could improve it still further slightly, but I did not want to spend the time. I had not previously tried to find the setting for this LP. The next LP was the Carole King LP. I saw that it was thinner, so I moved my arm down to 17mm as a guess because it was Ron's LP. It sounded wrong, so I went to 16.5mm. That was better, but I knew it could be improved further still. I moved it down another 0.5mm to 16mm and it sounded even better. Each move took roughly 30 seconds to adjust the arm. No big deal. No tricks, just better sounding music.
The first night I played my system for Ron we heard Johny Hartman (small scale jazz band and single voice plus guitar), Cantata Domino (large scale organ, trumpets and choir, then solo soprano, then male and female choir), and finally the Sheffield Drum Track (solo drum). I never touched the arm height. Each of these three LP had the same SRA setting based on listening from years ago, so Ron and I basically just sat and enjoyed an hour of music and flipped records like everyone else.
It was only when Ron played his own LPs with which I was unfamiliar and had not previously found a proper SRA that we spent a few minutes adjusting. I simply wanted to show Ron what I do. I had no intention of proving anything or of convincing him how to approach vinyl playback.
I agree with Fransisco, none of this is new.
